PTCA
write_chan(dev, PTCA, 0, 0);
write_chan(dev, PTCA, 1, 0);
write_chan(dev, PTCA, 3, 0);
write_chan(dev, PTCA, i, 0);
write_reg(dev, PTCA, i, 0);
write_reg(dev, PTCA, i, 0);